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ibv_dereg_mr(3) [debian man page]

IBV_REG_MR(3)						  Libibverbs Programmer's Manual					     IBV_REG_MR(3)

NAME

       ibv_reg_mr, ibv_dereg_mr - register or deregister a memory region (MR)

SYNOPSIS

       #include <infiniband/verbs.h>

       struct ibv_mr *ibv_reg_mr(struct ibv_pd *pd, void *addr,
				 size_t length, int access);

       int ibv_dereg_mr(struct ibv_mr *mr);

DESCRIPTION

       ibv_reg_mr()  registers	a  memory region (MR) associated with the protection domain pd.  The MR's starting address is addr and its size is
       length.	The argument access describes the desired memory protection attributes; it is either 0 or the bitwise OR of one  or  more  of  the
       following flags:

       IBV_ACCESS_LOCAL_WRITE  Enable Local Write Access

       IBV_ACCESS_REMOTE_WRITE	Enable Remote Write Access

       IBV_ACCESS_REMOTE_READ Enable Remote Read Access

       IBV_ACCESS_REMOTE_ATOMIC Enable Remote Atomic Operation Access (if supported)

       IBV_ACCESS_MW_BIND Enable Memory Window Binding

       If IBV_ACCESS_REMOTE_WRITE or IBV_ACCESS_REMOTE_ATOMIC is set, then IBV_ACCESS_LOCAL_WRITE must be set too.

       Local read access is always enabled for the MR.

       ibv_dereg_mr() deregisters the MR mr.

RETURN VALUE

       ibv_reg_mr()  returns  a  pointer to the registered MR, or NULL if the request fails.  The local key (L_Key) field lkey is used as the lkey
       field of struct ibv_sge when posting buffers with ibv_post_* verbs, and the the remote key (R_Key) field rkey is used by  remote  processes
       to  perform  Atomic  and  RDMA  operations.   The  remote  process  places  this rkey as the rkey field of struct ibv_send_wr passed to the
       ibv_post_send function.

       ibv_dereg_mr() returns 0 on success, or the value of errno on failure (which indicates the failure reason).

NOTES

       ibv_dereg_mr() fails if any memory window is still bound to this MR.

SEE ALSO

       ibv_alloc_pd(3), ibv_post_send(3), ibv_post_recv(3), ibv_post_srq_recv(3)

AUTHORS

       Dotan Barak <dotanba@gmail.com>

libibverbs							    2006-10-31							     IBV_REG_MR(3)

Check Out this Related Man Page

RDMA_POST_READ(3)					   Librdmacm Programmer's Manual					 RDMA_POST_READ(3)

NAME

       rdma_post_read - post an RDMA read work request.

SYNOPSIS

       #include <rdma/rdma_verbs.h>

       int  rdma_post_read  (struct  rdma_cm_id *id, void *context, void *addr, size_t length, struct ibv_mr *mr, int flags, uint64_t remote_addr,
       uint32_t rkey);

ARGUMENTS

       id	   A reference to a communication identifier where the request will be posted.

       context	   User-defined context associated with the request.

       addr	   The address of the local destination of the read request.

       length	   The length of the read operation.

       mr	   Registered memory region associated with the local buffer.

       flags	   Optional flags used to control the read operation.

       remote_addr The address of the remote registered memory to read from.

       rkey	   The registered memory key associated with the remote address.

DESCRIPTION

       Posts a work request to the send queue of the queue pair associated with the rdma_cm_id.  The contents of the remote memory region will	be
       read into the local data buffer.

RETURN VALUE

       Returns 0 on success, or -1 on error.  If an error occurs, errno will be set to indicate the failure reason.

NOTES

       For  a  list  of  supported  flags, see ibv_post_send.  Both the remote and local data buffers must have been registered before the read is
       issued, and the buffers must remain registered until the read completes.

       Read operations may not be posted to an rdma_cm_id or the corresponding queue pair until it has been connected.

       The user-defined context associated with the read request will be returned to the user through the  work  completion  wr_id,  work  request
       identifier, field.

SEE ALSO

       rdma_cm(7), rdma_connect(3), rdma_accept(3), ibv_post_send(3), rdma_post_readv(3), rdma_reg_read(3), rdma_reg_msgs(3)

librdmacm							    2010-07-19							 RDMA_POST_READ(3)
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